BackgroundPostpartum depression (PPD) is a form of depression that can occur after childbirth and is characterized by feelings of sadness. It is a common psychological problem that affects women and children. This study aimed to assess the association between PPD and risk factors, such as delivery mode, ABO blood group, and passive smoking in Saudi Arabia. MethodsPPD was assessed in this cross-sectional using an Arabic version of the Edinburgh postnatal depression scale through an online questionnaire distributed to women in Saudi Arabia between January and March 2022. The data were analyzed using SPSS version 26 (IBM Corp., Armonk, NY). ResultsA total of 354 postpartum women completed the questionnaire within six weeks of giving birth. Their mean age and BMI were 30.1±6.78 years and 25.98±5.84 kg/m 2 , respectively. PPD occurred in 56.2% of the participants. Elective cesarean section and operative vaginal delivery were associated with the presence of PPD symptoms in 17.6% and 7% of the women, respectively. The majority of those with third and fourth degrees and those who had instrumental assisted delivery had postpartum depression and this was statistically significant (p=0.017). About 26.6% of the participants were exposed to passive smoking, and 21.9% of them developed PPD. However, it was not statistically significant. Moreover, women with PPD were more likely to have blood type O+, followed by A+. Demographic factors did not show a significant correlation with developing PPD except for age (p=0.01), those who developed PPD were much younger on average than those who did not develop PPD (29.28±6.61 years vs. 31.15±6.86 years). ConclusionA significant association was found between PPD and the type of delivery. The association between PPD and passive smoking, ABO blood groups was insignificant. However, women who developed PPD were younger on average than those who did not develop PPD.